TileMapLayer, terrain and 2 tile walls

Godot Version

v4.4.1.stable.mono.arch_linux

Question

I want to make a terrain using the tileset format above, but I have no idea if this is even possible or where to start really. Each tile consists of a top component (32x32) and a front wall component (32x32). There are a lot of top variations but only 7 possible front wall configurations. I also need to place the top tile above where the actual solid part is, so it overlaps the floor behind - I will mask the wall somehow if the player walks behind it. Characters and items etc will have their origin set to the bottom so they draw half way up the tile and their top will show behind the wall.

I watched a lot of TileSetLayer tutorials but they all seem to show simple flat terrains with no 2 tile blocks, certainly nothing this complex. Hope someone can help!